Efficient farming is promoted through the use of tractor-drawn agricultural implements configured to include a relatively large plurality of ground-working tools. By such arrangements, a relatively wide path of soil can be worked by each pass of the tractor, with the plurality of tools of such implements typically arranged to work a corresponding plurality of rows attendant to each pass.
While some agricultural implements include tools which are positioned generally in alignment transversely of the implement, it is not uncommon for an implement to have its tools arranged in both transversely and longitudinally spaced relation on the implement frame. As will be appreciated, efficient cultivation dictates that the implement frame be maintained in a relatively level disposition so that all of the tools, including those in the forward "rank" as well as those in the rearward "rank", penetrate the soil to a generally uniform depth.
Previous agricultural implement constructions have not promoted uniform depth control to the desired degree. In order to first adapt a typical implement for the drawbar height of the associated tractor (which height can typically vary from one tractor to another), it has heretofore been necessary to adjust the implement in a relatively inconvenient manner entailing repositioning the implement hitch with respect to a plurality of adjustment holes. While such adjustment can level the implement for a particular tool depth setting, such adjustment mechanisms are ordinarily configured such that the implement is maintained in a level disposition only at that one particular depth setting. In other words, while the tools of most implements can be raised and lowered by suitable hydraulic operation of an implement's supporting wheels, implements of the above type are not configured to be maintained in a level disposition throughout the range of this vertical tool movement.
Accordingly, it is desirable to provide an agricultural implement construction which is configured to be maintained in a level disposition attendant to raising and lowering of the implement relative to the ground, to thereby promote uniform depth control of ground-working tools mounted on the frame of the implement throughout the range of vertical movement of the tools. It is further desirable to provide an implement whereby it can be readily adjusted for use with tractors having implement drawbars mounted at differing heights above the ground.